Civil rights protests against segregation, for example, would see protesters filling up or blocking restaurants that would refuse to serve black customers. Basically - you won't serve black people, we will put you out of business. Sometimes the police would come and arrest people, and that would win sympathy for the protesters, because even people who thought "Maybe black people shouldn't eat be allowed to eat at restaurants" might feel pangs of sympathy at seeing people arrested for just sitting at a restaurant counter.
Now, you can say "The trucker protest isn't as important as civil rights" but that's just a "You shouldn't be protesting" argument. Racists thought civil rights protesters shouldn't be protesting too. If the protesters believe their cause is actually important then it makes sense to protest. But, it only makes sense to protest in ways that are likely to result in changes. Symbols are fine, but empty symbolism isn't enough for something you think is really important.
